Existing sockets, as shown in FIG. 1A, generally include a socket cover 1. The socket cover 1 has conventional power connectors 21′, 22′. The conventional power connectors 21′, 22′ are used for connecting to AC (Alternate Current) line power, wherein the conventional power connector 22′ include two live holes. In comparison with the conventional power connector 22′, the conventional power connector 21′ further includes an earth hole. The socket can be mounted onto a wall. As shown in FIG. 1B, a conventional power connector 21′ is also included in the prior art. This conventional power connector 21′ is different from the conventional power connector 21′ as shown in FIG. 1A only by a certain difference in the shape of the connector, but the principles are the same.
Most existing sockets are solely used to provide AC line power connectors. The functions are relatively limited.